Radio method and apparatus



F. A. KOLSTER RADIO METHOD AND APPARATUS Aug. .24 1926.

Filed May 29, 1919 I l l l l l I l I l I I l I l I l l l l I l\ lNVl -I NTO ATTORNEY Patented Aug. 24, 1926.

UNITED STTES ATE FFNE.

FREDERICK A. KOLSTER, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO FEDERAL TELEGRAPH COMPANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORA- TION CALIFORNIA.

RADIO METHOD AND APPARATUS.

Application filed May 29,

My invention relates to apparatus for transmitting or receiving, or for transmitting and receiving electro-radiant energy or electro-magnetic waves for the transmission of intelligence, as for radio telegraphy or telephony, or for signaling in general, or for any other purpose.

My invention resides in apparatus for simultaneously transmitting and receiving telegraphic, telephonic or other messages without interference with each other and so enabling, particularly as regards radio telephony, the carrying on of conversation between widely separated stations in the .usual manner practiced with wire telephony, with out recourse to throwing of switches or change of connections. 7

My invention resides also in apparatus for simultaneously transmitting and receiving telegraphic, telephonic or other messages as above referred to by production of directional effects as regards reception.

My invention resides also in apparatus of the character above referred to, as well as to such apparatus when used for reception only, wherein reception is effected through an inductive coupling which is located in the center of one or more inductance coils comprised in a-closed circuit or circuits, preferably having very small distributed inductance and distributed capacity.

My invention resides in the apparatus hereinafter described and claimed.

For an illustration of some of the various forms my apparatus may take, reference is to be had to the accompanying drawing, in which:

Fig. 1 is a diagrammatic view illustrating apparatus embodying my invention.

F i 2 is a diagrammatic view of a modified f orm embodying my invention.

Referring to Fig. 1, A is a coil, preferably rotatable, asfor example, about a vertical axis, of one or more turns constituting a lumped inductance connected in series with the variable tuning condenser C. The distributed inductance and distributed capacity of this closed circuit are preferably substantially nil. The closed circuit, and particularly the coil A thereof, constitutes a capacity area with which may cooperate, if suitable or desired, an additional capacity area B of any suitable form, in the example illustrated ,an antenna-like capacity area.

1919. Serial No. 800,682.

When the additional capacity area or antenna B is employed, the switch 9 is closed, thereby connecting it to the aforesaid capacity area, such connection preferably being made at the middle of the coil A, as indicated at the point 6. In shunt to the varidistributed capacity and yet, as a capacity area, a maximum or large capacity with respect to earth or other capacity E, the coil A may have its neighboring convolutions or turns separated from each other by a suitable or considerable space a, whereby the distributed capacity effect due to capacity between neighboring turns or convolutions is reduced to a negligible amount or is substantially nil.

In shunt to the condenser C is connected any suitable 'detector D, here shown as a thermionic detector 0r audion, of any suitable structure or type, having the grid 11, filament f, heated by current from battery 9 and regulated byresistance h, and a plate, wing or anode j in whose circuit is the battery 7c and the device T, which may be a. telephone receiver or any other suitable device, as for example, a primary of a trans former or other suitable means for coopera-,

tion with one or more additional thermionic devices for effecting any suitable degree of amplification, and for beat reception, if de sired.

The apparatus thus far described is sub stantially similar to apparatus described and claimed in my prior Patent No. 1,447,165, February 27, 1923, having for reception the directive or uni-lateral efi'ects therein described.

With this apparatus is associated transmitting apparatus whereby spoken or other messages or signals may be received'without interference by energy simultaneously transmitted and which may represent spoken or other messages, whereby a telegraphic or telephonic communication may simultaneously be carried on between two widely separated stations without interference by the closed circuit, which is associated with the receiving apparatus or detector. The oscillations produced by the transmitting apparatus may be of the same frequency as the received energy, and though relatively very powerful as compared with the simultaneously received ener cause no interference or conflict with the atter. In other words, the-transmitter oscillations due to the symmetr of connection of the inductance L to the c osed circuit will not cause interference with simultaneously received weak energy. Accordingly a person ma hold to his ear the telephone associated with the detector D;

or the associated amplifying means, and speak into the microphone m, and so carry on a conversation, as in the case of ordinary wire telephony,'with a party equipped with similar or equivalent apparatus at a distant station. It will be noted that no switches or changes of connections are necessary to alternate between receiving and transmitting relations, but that both transmission an reception may simultaneously: occur without confusion.

It is preferable that around the oscillation producing means or around the transmitting apparatus be placed a conducting shell or screen, indicated in dotted lines by c, to prevent direct effect upon the receiving circuits of the locally produced oscillations of relatively high power. By use of such screen the oscillations produced in the inductance L have no effect upon the receiving ap aratus, but flow in symmetrical or divide paths into the capaclty area A, or A and B if the latter be used.

Referring to Fig. 2, the arrangement is in general the same as regards simultaneous transmission and reception of both spoken and telegraphic or other messa es, the trans mittin apparatus being as be ore associated with t e inductance L and again preferably enclosed in a screen or shell 0.

In this case there may be employed 0 not, as may be suitable or desired, any suitable ca acity area B. in this instance illustrated, y way of example merely, as a plate or equivalent capacity area. The coil or lumped inductance of the closed circuit is posed at an angle with respect toeach other.

In any event, the coil structure A A is preferably rotatable so as to procure 'the directive effects hereinbefore referred to. Disposed preferably at the physical and electrical. center of the inductance or coil structure A A is an inductive coupling between the closed circuit, comprising the coils A A and the adjustable condenser C, and the receiving circuit or apparatus includin a detector D with which may be associated \the telephone T or which may communicate to any number of steps of thermionic amplifying apparatus. The inductive coupling com rises t e transformer windings t and t, t e latter being variable and connected in series with the coils A A, and preferably located at their center, the capacity area B if employed, being brought into oporation by closure of the switch 9, the connection 'of this ca acity area being preferably at the electrical center of the system, that is, preferably at or near the middle of the transformer winding t. In circuit with the transformer secondary t is the variable condenser C, for tunin such circuit to the first mentioned closed circuit. In shunt to the condenser C is connected- .the ri'd circuit of the audion or similar thermionic detector D. In shunt to the variable condenser C, for tuning the closed circuit including the inductances A and A areserially connected the condensers C and C, each variable, and varied generally in opposite senses or complementarily. The inductance L is again connected to a point between these last named balancing or auxiliary condensers.

By employing the inductive coupling t, t particularl when electro-magnetic waves of great lengt are to be received, and connect- 1ng it and placing it as described, extremely high select vity is obtainable and extremely highl effective directional effects are obtainalile, and when the closed circuit is unsymmetrical with respect to the open or antenna path, uni-lateral reception is obtained. A

It will be understood that this inductive coupling arranged and disposed as described is of general ap lication to reception, regardless of simu taneous transmission and reception. However, it does .not interfere with simultaneous transmission and reception of the character referred to in connection with Fig. 1.

- In both Figs. 1 and 2 the closed circuits including the inductances are connected synnnetrically to the open antenna ath, electrical symmetry between the close C1I' cuit and the antenna path being wlth 'nicey obtainable by variation of condensers 1 and C While I have herein indicated two forms of capacity areas B, it will be understood that any other suitable form or type may be employed, and that all types may be interchangeably used with those indicated, and the forms indicated 'in Figs. 1 and 2 may be interchanged.

The coil orinductance structures hereinbefore referred to may be relatively small, such as may be suitable for portability, or may be relatively larger for permanent or stationary installations, and in either case ma be rotatable. a

s described in my aforesaid application, the dimensions of these coils or inductances may be very small as compared with the wave length received or transmitted.

The path through the inductance L of both figures and including the closed circuit as a capacity area may for brevity be referred to as an antenna path or structure, with the understanding that, particularly when the additional capacity area or antenna B is employed, such antenna path may have the structure or characteristics of high antenna structures now commonly employed in the art and thus have considerable distributed capacity and distributed inductance but, preferably, are of such structure, arrangement or size as to have relatively small or substantially no distributed capacity or distributed inductance.

As to both the open or antenna path and a the closed circuit or path, and articularly the latter, it. will be understoo that it is preferred that the ratio of inductance to capacity shall be large, whereby higher selectivity is procured; and as to the closed circuit associated with the receiving apparatus or detector such ratio affords a higher potential for impression upon the detector of potential operated type, as a thermionic device.

Both the open or antenna path and the closed circuit or path may be attuned or adjusted to the same or substantially the same wave length or to different wave lengths for both transmission and reception, and for simultaneous transmission and reception.

\Vith the closed circuit electrically symmetrical with respect to the open or antenna path, great amounts of energy may be impressed upon the open or antenna path for transmitting purposes without in any way 7 affecting the closed circuit and the receiving apparatus or indicating means associated therewith, If there should be lack of closed circuit.

perfect symmetry, some of the energy of the transmitting apparatus will be transferred to the closed circuit and so interfere riviug from a distant station. In such case,

however, it is only necessary to vary the condensers C and C, or either of them, to attain perfect electrical symmetry. is preferred, however, that the condensers C and C bevaried complementarily so that when varied they will not afi'ect ordestro the tuning. of the closed circuit.

W hen the coils A or A, A are rotatable, they may be so positioned: that their ver tical plane or planes coincide substantially with the vertical plane embracing also-the distant transmitting station, inwhich case a directional reception effect is obtained.

What I claim is 1. The combination with a closed circuit including a coil absorbing energy directly from the natural media and acondenser, of a. plurality of reactances in series with each other and in shunt to said condenser, an antenna path connected to a point between said reactances, means for impressing oscillations upon said antenna path, and receiving apparatus controlled by said closed circuit.

2. The combination with a closed .circuit' including a'rotatable coil absorbing energy directly from the natural media, and a con- 7 point between said reactances, means for impressing oscillations upon said antenna path, and receiving apparatus controlled by said closed circuit.

3. The combination with a coil having a plurality of turns absorbing energy direct-- 1y from thenatural media, of a closed circuit including said coil, an antenna connected to a mid-point between the remote terminals of said coil, serially connected reactances associated with said coil, a second antenna connected to a point between said reactances, receiving apparatus controlled by said closed circuit, and means for impressing oscillations upon one of said antennae. I

4. The combination with a coil having a plurality of turns absorbing energy directly from the natural media, of a closed circuit including said coil and a condenser, an antenna connected to a midoint between the remote terminals of sai coil, serially related reactances in shunt to said condenser, a second antenna connected to a point between said reactances, means .for impressing oscillations upon one of said antennae, and receiving apparatus controlled by said 5. The combination with a closed circuit comprising rotatable inductive means absorbing energy direct from the natural media and capacity, of receiving a paratus affected by ener received in sai circuit, an antenna pat s mmetrically connected with respect to sai inductive means, and transmitting apparatus associated only with said antenna path. 7

6. The combination witha closed circuit comprising rotatable inductive means havreceived in said circuit, an antenna pat comprising capacities between which said closed circuit is symmetrically connected,

- and transmitting apparatus associated only with said antenna ath.

8. The combination with a closed circuit comprising rotatable inductive means and capacity, of receiving apparatus afi'ected by energy received in said circuit, an antenna path com rising capacities with respect to which sai inductive means is symmetrically connected, and transmitting apparatus associated only with said antenna path.

9. The combination with a closed circult comprising an inductance'coil and capacity,

of receiving apparatus affected by energy received in said circuit, an antenna path comprising capacities between which said closed circuit is symmetrically connected, transmitting apparatus, and an inductive coupling between said transmitting apparatus and said antenna path only.

10. The combination with a closed circuit comprising an inductance coil and a plural- 'ity of capacities, of receiving apparatus af-,

fected by energy received in said, circuit, an antennav path symmetrically connected to said closed circuit at a point between said capacities, and transmitting apparatus associated only with said antenna path.

11. The combination with a closed circuit comprising a plurality of capacities and rotatable inductive means having a plurality of turns absorbingenergy directly from the natural media, of receiving apparatus af- -fected by energy received in said circuit, an antenna path symmetrically connected with respect to said inductive means at a point between said capacities, and transmitting applaratus associated only with said antenna at i. I p 12. The combination with a closed circuit comprising an inductance coil and a plural- I .ity of capacities, of receiving apparatus affected by energy received in said circuit, an

antenna path symmetrically connected said closed circuit at a point between said int capacities and at substantially the midcirof the entire inductance in said close cuit, and transmitting apparatus associated only with said antenna atn.

13. The combination with a closed circuit comprising capacity and inductance coils absorbing ener' directly from the natural media, of receiving apparatus, and an inductive cou ling between said receiving aparatus an ing comprising a winding dis stantially the center of sai coils in the. circuit thereof.

14. The combination with a closed circuit comprising capacity and inductance coils absorbing energy directly from the natural media, of receiving apparatus, and .an insed at an inductance ductive coupling between said receiving ap-- paratus an said closed circuit disposed at substantially the center of said inductance co1ls,' said mductance coils being rotatable 1 independently of said coupling.

15. The combination with a closed circuit comprising capacity and inductance coils' absorbing energy directly from the natural media, of receiving apparatus, an inductive coupling between said receiving apparatus and said closed circuit, said coupling comprising a winding disposed at substantially the center 0t said inductance coils, and an antenna circuit symmetrically connected to said closed circuit.

16. The combination with a closed circuit comprising capacity and inductance coils absorbing energy directly-from the natural media, of receiving apparatus, an inductive coupling between said receiving apparatus and said closed circuit disposed at substantially the center of said inductance coils, said inductance coils being rotatable independently of said coupling, and an antenna circuit symmetrically connected to said closed circuit.

17. The combination with a closed circuitcomprising capacity and inductance coils, of receiving apparatus, an inductive coupling between said receiving apparatus and said closed circuits disposed at substantially the center of said inductance coils, an antenna circuit comprising capacities connected to said closed circuit at symmetrically'opposite points thereof, one of said capacities connected to substantially the middl of a coil of said coupling.

18. The combination with a closed circuit comprising capacityand rotatable in said closed circuit, said coupprising capacities connected to said coils at symmetrically opposite points thereof, or c of said capacities connected to substantial? the middle of a coil of'said coupling.

19. The combination with a closed circuit comprising capacity and inductance coils absorbing energy directly from the natural media, of receiving apparatus, an inductive couplin between said receiving apparatus and sa1d closed circuit disposed at substantially .the center of said inductance coils, an antenna circuit symmetrically connected to said closed circuit, and transmitting apparatus associated only with said antenna path.

20. The combination with a closed circuit comprising capacity and rotatable inductance coils absorbing energy directly from the natural media, of receiving apparatus, an inductive coupling between sa1d receiving-apparatus and sa1d closed circuit dis osed at substantially the center of said in uctance coils, an antenna circuit symmetrically connected to said coils, and transmitting apparatus associated. only with said antenna path.

21. The combination with a closed circuit comprising capacity and inductance coils, of receiving apparatus, an inductive couplin I between said receiving apparatus and said closed circuit disposed at substantially the center of said inductance coils, an antenna circuit comprising capacities connected to said closed circuit at symmetrically opposite points thereof, one of said capacities connected to substantially the middle of a coil of said coupling, and transmitting apparatus associated only with sa1d antenna path.,

22. The combination with a 'closed circuit comprising capacity and rotatable inductance "coils, absorbing energydirectly. from the natural media, of receiving apparatus, an inductive coupling between said receiving apparatus and said closed circuit disposed at substantially the center of sa1d inductance coils, an antenna. circuit comprising capacities connected to said coils at symmetrically opposit points thereof, one of said capacities connected to substantially the middle of a coil of said coupling, and transmitting apparatus associated only with said antenna path.

23. The combination with a closed circuit including capacit and a. divided inductance coil absorbing energy directly from the natural media, of receiving apparatus afi'ected by said closed, circuit, and means for couplm said receiving apparatus to said closed circuit comprising a coupling coil connected between the parts of said inductance coil and in series with them in said closed circuit.

24. The combination with a closedcircuit including p i y nd a d ided anected to said closed circuit, and means for I I varyin th symmetry of said closed circuit with respectto said antenna path.

25.. The combination with a closed circuit comprising an inductance, an. antenna path, means for symmetrically relating said path and said closed circuit with respect to each other, receiving apparatus co-acting with one of them, and transmitting apparatus co-acting only with the other of them, saidmeans comprising a plurality of complementarlly variable condensers at a point between which said antenna path and said closed circuit are connected to each other.

26. Apparatus 'for transmitting and simultaneously directively receiving high frequency energy, as electro-radiant energy,

comprising a closed circuit including a rotatable c011, signal translating means controlled by the energy receivedin said closed circuit from apredetermined direction with respect to which said coil is positioned, an antenna path symmetrically related to said closed circuit, and transmitting apparatus associated only with said antenna path.

. 27. Apparatus for simultaneous transmission and reception of high frequency energy, as electro-radiant energy, comprising a circuit including an inductance coil and capacity, of indicatingmeans afl'ected by energy absorbed in said circuit, an antenna path, transmitting apparatus associated only with said antenna path, and means -for preventing effect of the transmission upon the reception comprising a plurality of means, one for shielding the receiving apparatus from direct effect of the energy of said transmitting apparatus and another for symmetrically relating said circuit with respect to said antenna path.

28. The combination with aclosed circuit including capacity'and a divided inductance coil absorbing energy directly from the natural media, of a coupling coil connected between the and in series erewith in said closed circuit, receiving apparatus controlled by said plarts of said inductance coil I t coupling coil, and an antenna connected to a n 947 r ith in said cl s d, h m 13c coupling coi a plurality of serially related reactances assoclated with said closed circuit, and an antenna path connected to a point between said reactances.

30. The combination with a closed circuitincluding capacity'and a divided inductance coil absorbing energy directly from the natural media, of a couplin coil connected between the parts of said in uctance coil and in series therewith in said closed circuit, receiving a paratus controlled by said coupling coi a plurality of serially related reactances associated with said closed circuit, and an antenna path connected to said closed circuit.

31. The combination with a closed circuit including capacity and a divided inductance coil absorbing energy directly from the natural media, of a coupling c011 connected between the arts of said mductance coil and in series t erewith in said closed circuit, receiving apparatus controlled by said coupling coil, a reactan'ces associated with said closed circuit, an antenna path connected to said closed circuit, and means for varying the natural period of said antenna path. 7

32. The combination with a closed circuit including a loop antenna and a reactance, of reactances connected in series with each other in a path in shunt to said reactance, an antenna connected to a point between. said serially related reactances, transmitting apparatus for efi'ecting oscillations in one of said antennae, and receiving apparatus controlled by the other of said antennae.

33. The comblnation with a closed circuit comprising a loop antenna and a capacity, of a plurality of reactances connected series with each other in a path in shunt to said condenser, an antenna connected to a point between said serially related reactances, transmitting apparatus for efiectin oscillations in one of; said antennae, an receiving apparatus controlled by the other of said antennae.

34. The combination with a closed circuit comprising a loop antenna and a capacity, of a plurality of capacities connected 'in series with each other, in a path in shunt to plurality of serially related said capacity, an antenna connected to a point between said serially related capacities, transmitting apparatus for effecting oscillations in one of said antennae and receivi apparatus controlled by the other ofsai including capacity and inductance coils, said inductance coils efiecting direct transfer between themselves and the natural media of a substantial portion of the entire energy interchanged between said closed circuit and the natural media, of a circuit, and means for coupling said circuit to said closed circuit at a region between said inductance coils.

37. The combination with a closed circuit including capacity and inductance coils, said inductance coils effecting direct transfer between themselves and the natural media of a substantial portion of the entire energy interchanged between said closed circuit and the natural media, of a circuit, means for coupling said circuit to said closed circuit at a region between said inductancecoils, and

an antenna connected to said closed circuit.

38. Thecombination with a closed circuit including capacity. and inductance coils, said inductance coils efiecting direct transfer between themselves and the natural media of a substantial portion of the entire energy interchanged between said closed circuit and the natural media, of a circuit, means for coupling said'circuit to said closed circuit at a region between said inductance coils,

.and an antenna connected to said closed cir- FREDERICK A. KOLSTER.

-transfer relation with the- 

